src/test/ui/liveness/liveness-dead.rs

#![allow(dead_code)]
#![deny(unused_assignments)]

fn f1(x: &mut isize) {
    *x = 1; // no error
}

fn f2() {
    let mut x: isize = 3; //~ ERROR: value assigned to `x` is never read
    x = 4;
    x.clone();
}

fn f3() {
    let mut x: isize = 3;
    x.clone();
    x = 4; //~ ERROR: value assigned to `x` is never read
}

fn f4(mut x: i32) { //~ ERROR: value passed to `x` is never read
    x = 4;
    x.clone();
}

fn f5(mut x: i32) {
    x.clone();
    x = 4; //~ ERROR: value assigned to `x` is never read
}

fn main() {}